1. Field of the Invention
The present invention relates to improvements in friction clutches, particularly in self-adjusting clutches that can automatically compensate for wear of their friction linings, pressure plates, counterpressure plates and/or other components that are subject to wear during use of the clutch, for example, between the prime mover (such as an internal combustion engine) and the change-speed transmission or gearbox in the power train of a motor vehicle.
2. Description of the Related Art
A friction clutch of the type to which the present invention pertains normally includes a diaphragm spring or a Belleville spring that is tiltably mounted in a rotary housing in such away that it must share the angular movements of the housing but has limited freedom of axial movement relative thereto. The pressure plate cooperates with a counterpressure plate, such as a flywheel that rotates with the housing and cooperates with the pressure plate, to clamp, with or without slippage, the friction linings of a so-called clutch plate or clutch disc when the clutch is engaged, either entirely or in part (that is, without or with slip between the pressure plate and the counterpressure plate on the one hand, and the clutch disc on the other hand). The counterpressure plate can receive torque from the rotary output element of a prime mover to rotate the housing and the pressure plate, and the clutch disc can drive the rotary input element of the gearbox when the clutch is at least partially engaged.
Self-adjusting clutches are disclosed, for example, in German patents Nos. DE 4306505 A1, DE 42 39 289 A1 and DE 43 22 677 A1. Reference may also be had to commonly-owned U.S. Pat. No. 5,409,091 (granted on Apr. 25, 1995 to Reik et al. and entitled “AUTOMATICALLY ADJUSTABLE FRICTION CLUTCH”) and U.S. Pat. No. 5,450,934 (granted on Sep. 19, 1995 to Maucher and entitled “FRICTION CLUTCH”).
Friction clutches of the type to which the present invention pertains are designed in such away that at least a portion of the closing or engaging force that determines the magnitude of transmittable torque is introduced into the clutch from the outside by the diaphragm spring. The diaphragm spring preferably includes a ring-shaped main or primary portion of variable conicity, and actuating levers in the form of prongs or tongues that extend from the radially inner side of the main portion. Such prongs can be and preferably are of one piece with the main portion of the diaphragm spring.
An object of the present invention is to provide a novel and improved friction clutch that can be utilized with advantage in the power trains of motor vehicles, particularly to transmit torque between the rotary output element (such as a crankshaft or a camshaft) of a prime mover (for example, an internal combustion engine) and the rotary input element (such as a shaft) of a change-speed transmission or gearbox in the power train.
Another object of the invention is to provide a novel and improved self-adjusting friction clutch that can automatically compensate for wear of the friction linings of its clutch plate or clutch disc and certain other parts that undergo wear in response to repeated engagement and disengagement of the clutch.
A further object of the invention is to provide a novel mounting of the diaphragm spring in the housing of a self-adjusting friction clutch.
An additional object of the invention is to provide groups of preassembled parts that can be joined to constitute an improved friction clutch for use in the power trains of motor vehicles.
Still another object of the invention is to provide a novel and improved power train that can be utilized in motor vehicles and that includes the above-outlined self-adjusting friction clutch.
An additional object of the invention is to provide a novel and improved combination of a diaphragm spring, housing, and pressure plate for use in a friction clutch, particularly a self-adjusting clutch for use in the power trains of motor vehicles.
A further object of the invention is to provide a novel and improved multiple clutch unit that includes at least one self-adjusting friction clutch of the above-outlined character.